Carbon diselenide

Carbon diselenide
Names



Other names Carbon selenide, diselenoxomethane, methanediselone
Identifiers
CAS Number	506-80-9^Y
3D model (Jmol)	Interactive image
ChemSpider	61481^N
ECHA InfoCard	100.007.323
PubChem	68174
InChI InChI=1S/CSe2/c2-1-3^N Key: JNZSJDBNBJWXMZ-UHFFFAOYSA-N^N InChI=1/CSe2/c2-1-3 Key: JNZSJDBNBJWXMZ-UHFFFAOYAM
SMILES [Se]=C=[Se]
Properties
Chemical formula	CSe₂
Molar mass	169.93 g/mol
Appearance	yellow liquid
Density	2.6824 g/cm³
Melting point	−43.7 °C (−46.7 °F; 229.5 K)
Boiling point	125.5 °C (257.9 °F; 398.6 K)
Solubility in water	0.054 g/100 mL
Solubility	soluble in CS₂, toluene
Dipole moment	0 D
Thermochemistry
Specific heat capacity (C)	5032 J/mol K
Std molar entropy (S^o₂₉₈)	263.2 J/mol K
Std enthalpy of formation (Δ_fH^o₂₉₈)	219.2 kJ/mol
Hazards
Flash point	30 °C (86 °F; 303 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is ^YN ?)
Infobox references

Carbon diselenide is an inorganic compound with the chemical formula CSe₂. It is a yellow-orange oily liquid with pungent odor. It is an analogue of carbon disulfide (CS₂). This light-sensitive compound is insoluble in water and soluble in organic solvents.

Synthesis, structure and reactions

Carbon diselenide is a linear molecule with D_∞h symmetry. It is produced by reacting selenium powder with dichloromethane vapor near 550 °C.^[1]

2 Se + CH₂Cl₂ → CSe₂ + 2 HCl

It was first reported by Grimm and Metzger, who prepared it by treating hydrogen selenide with carbon tetrachloride in a hot tube.^[2]

Like carbon disulfide, carbon diselenide polymerizes under high pressure. The structure of the polymer is thought to be a head-to-head structure with a backbone in the form of –[Se–C(=Se)–C(=Se)–Se]–.^[3] The polymer is a semiconductor with a room-temperature conductivity of 50 S/cm.

In addition, carbon diselenide is a precursor to tetraselenafulvalenes,^[4] the selenium analogue of tetrathiafulvalene, which can be further used to synthesize organic conductors and organic superconductors.

Carbon diselenide reacts with secondary amines to give dialkydiselenocarbamates:^[1]

2 Et₂NH + CSe₂ → (Et₂NH₂⁺)(Et₂NCSe₂⁻)

Safety

Carbon diselenide has high vapor pressure. It has a moderate toxicity and presents an inhalation hazard. It may be dangerous due to its easy membrane transport. It decomposes slowly in storage (about 1% per month at –30 °C). When obtained commercially, its cost is high.^[5]

Mixed with air, carbon diselenide releases an extremely offensive odor.^[6] Its smell forced an evacuation of a nearby village when it was first synthesized in 1936. The stench can be neutralized by oxidizing with bleach.^[7] Because of the odor, synthetic pathways have been developed to avoid its use.^[8]

References

1 2 Pan, W.-H.; Fackler, J. P. Jr.; Anderson, D. M.; Henderson, S. G. D.; Stephenson, T. A. (1982). "2. Diselenocarbamates from Carbon Diselenide". In Fackler, J. P. Jr. Inorganic Syntheses. 21. pp. 6–11. doi:10.1002/9780470132524.ch2. ISBN 978-0-470-13252-4.
↑ Grimm, H. G.; Metzger, H. (1936). "Über Darstellung und Eigenschaften des Selenkohlenstoffs". Berichte der deutschen chemischen Gesellschaft (A and B Series). 69 (6): 1356–1364. doi:10.1002/cber.19360690626.
↑ Carraher, C. E. Jr.; Pittman, C. U. Jr. (2005). "Poly(Carbon Disulfide), Poly(Carbon Diselenide), and Polythiocyanogen". Inorganic Polymers. 21. doi:10.1002/14356007.a14_241. ISBN 3-527-30673-0.
↑ Engler, E. M.; Patel, V. V. (1974). "Structure control in organic metals. Synthesis of tetraselenofulvalene and its charge transfer salt with tetracyano-p-quinodimethane". Journal of the American Chemical Society. 96 (23): 7376–7378. doi:10.1021/ja00810a042.
↑ "Carbon Diselenide CSe₂". Cse2.com. Retrieved 2012-04-04.
↑ Wolfgang H. H. Gunther. Organic Selenium Compounds: Their Chemistry and Biology. carbon diselenide has by far the worst odor this author has experienced in his lifetime of working with selenium compounds
↑ Lowe, Derek. "Things I Won't Work With: Carbon Diselenide". In the Pipeline. Science. Retrieved 20 November 2015.
↑ US patent 4462938, Wudl, F., "Process for producing chalcogen containing compounds", issued 1984-07-31, assigned to AT&T Bell Laboratories .

Inorganic compounds of carbon and related ions

Compounds	CBr₄ CCl₄ CF CF₄ CI₄ CO CO₂ CO₃ COS CS CS₂ CSe₂ C₃O₂ C₃S₂ SiC

Carbon ions	Carbides [:C≡C:]^2–, [::C::]^4–, [:C=C=C:]^4– Cyanides [:C≡N:]^– Cyanates [:O-C≡N:]^– Thiocyanates [:S-C≡N:]^– Fulminates [:C≡N-O:]^– Thiofulminates [:C≡N-S:]^–

Oxides and related	Oxides Metal carbonyls Carbonic acid Bicarbonates Carbonates

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